Explainer

The Tektite II underwater habitat in the U.S. Virgin Islands in 1970

NASA tracked 48 Tektite II aquanauts in five-person crews beneath the Caribbean for up to 30 days and found that private space, steady topside support and relief from isolation helped protect mood, work routines and life inside the habitat

The NASA report on Tektite II reads like an early manual for environmental psychology in space. During the 1970 missions off St. John, 48 aquanauts lived in five-person teams under the sea for 14, 20, or 30 days while researchers tracked attitudes, moods, complaints, leisure and work. NASA wanted more than marine science. It wanted…

Older adults exercising together in an indoor swimming pool

Health Explainer

Forty-six older adults with mild cognitive impairment spent 12 weeks doing moderate water workouts three days a week and the group that added in-pool number and color recall improved too, but it showed no significant cognitive or fitness advantage over exercise alone

Blurred reflection of a person in water with serene evening lighting capturing a tranquil mood

Health Explainer

Twelve older adults spent an hour in 40°C water two to three times a week and after six weeks some memory and reasoning scores improved while sleep and Alzheimer linked blood markers stayed unchanged

Women participating in a water aerobics class under the sun in West Java, Indonesia

Health Explainer

Fifty-six older adults with diabetes, hypertension and depression followed the same 40-minute HIIT water routine once or twice a week and only the twice-weekly group showed better sleep, less daytime drowsiness, lower anxiety and a 62 percent drop in depression symptoms

Lock down and Self-quarantine with new fish and tank decoration. Recreation at green garden during the Corona virus crisis. Stay home for relax and Social distancing

Humans Explainer

Thirty office workers took 10-minute breaks with live fish, a fish video, or quiet rest and the clearest psychological benefit came from stepping away from work, while the live tank still felt more engaging to participants

Visitors watching marine life in a large public aquarium exhibit

Humans Explainer

Researchers watched a 550,000-liter aquarium grow from bare water to 22 species and 151 animals, and as marine life returned visitors stayed longer, felt better and showed larger drops in heart rate

Peaceful scene of a large sailing ship with white sails on a tranquil sea during the day

Humans Explainer

Forty psychiatric outpatients in South Sardinia spent six months learning to sail and showed better symptoms and day-to-day functioning while the cruises lasted, but most of those rehabilitation gains had faded by the follow-up year

A man preparing for an indoor pool therapy or exercise session

Health Explainer

Veterans with documented PTSD completed up to eight trauma-informed warm-water therapy sessions and average PCL-M symptom scores fell by 14.4 points in a retrospective study that could not separate the pool treatment from other influences

In a heated pool, veterans with documented PTSD were guided through slow supported movements and breath cues with close one-to-one care. A 2025 retrospective study indexed by PubMed reported that the group who completed follow-up testing had much lower symptom scores after the program than they had before it. The headline number was a 14.4…

Three seafarers navigating from a ship's bridge

Humans Explainer

A survey of 1,231 Chinese seafarers and a memory experiment with 177 more suggest that loneliness can weaken work engagement by eroding cognitive flexibility, inhibitory control and working memory

Life at sea can keep people surrounded by crewmates while still leaving them cut off from the relationships that usually steady daily life. In this study, that feeling was linked to lower work engagement and the pattern appeared in both a large survey and a smaller experiment that briefly pushed participants to relive lonely moments…

Humans Explainer

Twenty-nine submariners spent 60 to 80 days aboard a ballistic missile submarine and regular exercise helped preserve alertness, balance and distance vision even as mood worsened during patrol and sleep and health scores declined after returning home

Twenty-nine submariners volunteered for an unusual mental-health study during a 60 to 80 day patrol aboard the French nuclear-powered ballistic missile submarine Le Triomphant. Researchers wanted to know whether regular onboard exercise could help men endure an environment built around confinement, isolation, artificial light, constant noise and a watch schedule that can pull sleep and…

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